1. Field of the Invention
The present invention relates to a video decoding and more particularly, to a method for decoding data encoded by bit rate control.
2. Description of the Related Art
A conventional video encoder uses bit rate control to keep the bandwidth of a bit stream within a predetermined range. The bit rate control scheme keeps the bandwidth of the bit stream constant by controlling at least a quantization value that determines picture quality. However, the change of the quantization value leads to fluctuation of the picture quality, which is the main cause of picture flickering and low-quality video.
To reduce the bit rate control-incurred change of video quality in the video encoder, a video decoder should be aware of the level of picture quality. For this purpose, the Peak Signal to Noise Ratio (PSNR) of an original video is calculated during encoding and is provided to the video decoder on a separate channel. Thus, this conventional video encoding/decoding technology requires an additional device for performing a PSNR calculation and an additional channel to deliver information about the picture quality level to provide the picture quality level information to the video decoder.